The circle - the rest are polygons.
No, a parallelogram is not a triangle because a parallelogram has four sides whereas a triangle has only three sides
The answer depends on how the parallelogram in the triangle is constructed.
I don't know about the relation in the perimeters of a triangle and a parallelogram but if a triangle is on the same base on which the parallelogram is and the triangle is between the same parallel lines of the parallelogram, then the area of the triangle will be half the area of the parallelogram. That is, area of a triangle = 1/2 area of a parallelogram if the triangle is on the same base and between the same parallel lines.
you do it because the triangle is half the size of the parallelogram
No - a triangle by definition has 3 sides. A parallelogram has 4.
No, a triangle is not a a parallelogram
No because a triangle has 3 sides whereas a parallelogram has 4 sides but they are both types of polygons
Parallelogram, rhombus and triangle
If the heights and bases are the same, then the triangle is half the area of the parallelogram.
No. A triangle has 3 sides, and a parallelogram has 4 sides. No kind of triangle can be a parallelogram, and no kind of parallelogram can be a triangle. The question is a lot like asking: Can this particular model of Toyota be a Ford ?